A recycling method of waste ternary battery

Abstract

The application discloses a recycling method of waste ternary batteries, and belongs to the technical field of material recycling. The method comprises the following steps: firstly, disassembling waste ternary batteries to obtain pole pieces; secondly, removing impurities in a vacuum state; thirdly, separating and recycling active substances; and finally, repairing and regenerating the active substances by a specific repairing method. The method can effectively avoid the use of high-pollution and high-cost reagents such as strong acid and strong base, and the processing condition is mild, and the repairing and regeneration can be realized under normal pressure. The impurity content of the positive electrode material obtained by the repairing and regeneration is low, and the electrochemical performance is excellent.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of material recycling, in particular to a recycling method of waste ternary batteries. BACKGROUND

[0002] The waste ternary batteries contain a large amount of metal elements such as lithium, nickel and manganese. If not recycled in time, not only these metal resources will be wasted, but also environmental pollution will be caused. At present, there are three main methods for recycling waste ternary batteries: pyrometallurgical recovery, wet extraction recovery and direct recovery. The pyrometallurgical recovery is to directly burn the waste ternary batteries by high-temperature smelting process, and then to chemically separate the recyclable elements. This method is simple to operate, but has high energy consumption and low recovery degree. The wet extraction recovery is to segmentally extract and recover different materials by different extractants. Although this method can achieve a high recovery level and relatively low energy consumption, the operation process is very complex, involves many types of extraction reagents, and may also produce new pollution sources. The direct recovery is to recover the materials separated by physical screening by physical means. This method has high impurities in the recovered materials and unstable quality. SUMMARY

[0003] The present application aims to overcome the shortcomings of the prior art and provides a recycling method of waste ternary batteries. The method first disassembles the waste ternary batteries to obtain the electrode sheet, then removes impurities in vacuum, separates and recovers the active material, and finally repairs and regenerates the active material by a specific repair method. This method can effectively avoid the use of high-pollution and high-cost treatment reagents such as strong acid and strong base, and has mild processing conditions that can be realized under normal pressure. The positive electrode material obtained by repair and regeneration has low impurity content and excellent electrochemical performance.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows:

[0005] A recycling method of waste ternary batteries, comprising the following steps:

[0006] Disassembling the waste ternary batteries to obtain a positive electrode sheet;

[0007] Calcining the positive electrode sheet at a vacuum degree of -0.1 to -0.2 MPa and a temperature of 100 to 200℃ for 0.5 to 2 hours to obtain a pretreated positive electrode sheet;

[0008] Placing the pretreated positive electrode sheet into an organic extraction liquid and ultrasonically stirring at 80 to 150℃ for 0.5 to 1 hour. After the suspension is allowed to stand, solid-liquid separation is performed. The obtained solid is ultrasonically stirred under the same conditions, and the process is repeated three times. The obtained precipitate is washed, subjected to solid-liquid separation, dried, and pulverized to obtain a separated active material;

[0009] The lithium content of the separated active material is detected and the lithium deficiency is determined, then the separated active material is crushed in water and an organic lithium salt or its derivative is added according to the lithium deficiency, and an additive is added for mixing, the obtained mixed solution is stirred and reacted at 80-100 DEG C for 1-4h, and water is added in real time during the reaction to maintain the water level unchanged; after the reaction is completed, the separated solid is dried and crushed to obtain the repaired active material; the additive is a mixture of ascorbic acid and hydrogen peroxide, and the volume percentage concentration of the additive in the mixed solution is 0.1-0.5vol%.

[0010] The repaired active material is mixed with an inorganic lithium source and calcined at 750-900 DEG C for 3-6h in an air or oxygen atmosphere to obtain the repaired and regenerated positive electrode material.

[0011] In the recycling method of the waste ternary battery described herein, compared with the method of directly soaking the positive electrode sheet in strong acid and strong base in the prior art, the positive electrode sheet is first treated by low-temperature vacuum impurity removal. This treatment not only effectively accelerates the rapid volatilization of the residual electrolyte in the positive electrode sheet, but also rapidly deactivates the binder (such as PVDF) contained in the positive electrode sheet. Subsequently, under the action of the organic extracting solution, the active material in the positive electrode sheet can be separated from the impurities such as binders at a temperature of only 80-150 DEG C, obtaining active material with high purity. Subsequently, in order to repair the active material by lithium supplementation, an organic lithium salt is introduced when lithium salt is introduced. The applicant found through experiments that, compared with inorganic lithium salt, the use of organic lithium salt or its derivative as a lithium source for lithium supplementation can promote the volatilization of impurity ions during subsequent high-temperature solid-phase calcination, thereby improving the purity of the positive electrode material obtained by recycling and regeneration. On the other hand, a specific additive needs to be introduced during the lithium supplementation reaction. This additive can effectively improve the redox kinetics of the re-lithiation of the active material, reduce the energy barrier of the reaction, and thus effectively reduce the required conditions for the reaction. Therefore, the lithium supplementation stage can be directly carried out under normal pressure, effectively reducing energy consumption. Finally, the repaired active material is mixed with an inorganic lithium source (used to supplement the lithium loss during calcination) and subjected to high-temperature calcination to fix the crystal phase, thereby obtaining the repaired and regenerated ternary positive electrode material. This material has high purity and high electrochemical activity, and can be directly used to prepare the positive electrode sheet of a ternary battery.

[0012] In an embodiment, the positive electrode material in the waste ternary battery is a nickel-cobalt-manganese positive electrode material, and the elemental molar ratio of nickel, cobalt and manganese in the positive electrode material is (1-8):(1-2):(1-4).

[0013] In the recycling method of the waste ternary battery described herein, the treatment object can be any one of the commonly used NCM111, NCM424, NCM523, NCM622 or NCM811 system batteries, as long as it is a normal retired, not damaged or significantly expanded waste battery.

[0014] In an embodiment, when the pre-processed positive electrode sheet is placed in the organic extraction liquid for ultrasonic stirring treatment, the solid-liquid ratio of the pre-processed positive electrode sheet to the organic extraction liquid is 1:(2-4); the organic extraction liquid is at least one of pyrrolidone, N,N-dimethylformamide, and dimethyl sulfoxide; the frequency during the ultrasonic stirring treatment is 20-25 kHz, the power is 30-35 kW, and the stirring speed is 60-120 r / min.

[0015] Due to the previous vacuum impurity removal stage, the electrolyte in the positive electrode sheet has been mostly removed, and the remaining inorganic material binder is also deactivated during the heating process, so that effective separation from the active material can be achieved by ultrasonic-assisted low-heat treatment in a conventional organic extraction liquid.

[0016] In an embodiment, the standing time of the suspension after ultrasonic stirring treatment is 2-4 h.

[0017] In an embodiment, when the separated active material is subjected to lithium content detection, an inductively coupled plasma emission spectrometer is used for detection, the amount of lithium deficiency detected is x, where the unit of x is mol, and the molar ratio of lithium in the organic lithium salt to lithium in the separated active material is ≥x.

[0018] In an embodiment, the stirring speed of the mixed solution containing the separated active material, the organic lithium salt, and the additive during stirring reaction is 200-600 r / min.

[0019] Further, the organic lithium salt is at least one of lithium acetate, lithium lactate, LiCF3SO3, and LiN(SO2CF3)2.

[0020] In an embodiment, the mass ratio of ascorbic acid to hydrogen peroxide in the additive is 1-9.

[0021] Through experimental exploration, when the two are within this ratio range, the degree of reduction of the lithium supplement reaction energy level of the active material is the largest, and the degree of lithium supplement can be further improved.

[0022] In an embodiment, the water content of the repaired active material is ≤1 wt%, and the average particle size is 8-12 μm.

[0023] In an embodiment, the inorganic lithium source is lithium carbonate, and the molar ratio of the repaired active material to lithium carbonate is 1:0.01-0.05.

[0024] In an embodiment, the heating rate during the mixing and calcination of the repaired active material and the inorganic lithium source is 2-5°C / min.

[0025] Compared with the prior art, the beneficial effects of the present application are:

[0026] Provided herein is a recycling method of waste ternary batteries, which comprises the following steps: firstly, disassembling waste ternary batteries to obtain electrode sheets; then, removing impurities under vacuum, separating and recycling active materials, and finally, repairing and regenerating the active materials by a specific repairing method. The method can effectively avoid the use of high-pollution and high-cost reagents such as strong acid and strong base, and the processing conditions are mild and can be realized under normal pressure. The impurity content of the positive electrode material obtained by repairing and regeneration is low, and the electrochemical performance is excellent. The reversible specific capacity of the lithium ion battery assembled therefrom reaches 155-170 mAh / g, and the initial efficiency reaches more than 85%, indicating that the product obtained by recycling can be comparable to new ternary positive electrode materials, and meets the integrated industrial system of recycling, repairing and regeneration, and application of waste ternary batteries. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 Scanning electron microscope images of the separated active material (a) and the repaired and regenerated positive electrode material (b) obtained in Example 2 described herein.

[0028] Figure 2 XRD test comparison result graph of the separated active material and the repaired and regenerated positive electrode material obtained in Example 2 described herein and the pure material new material. DETAILED DESCRIPTION

[0029] In order to better illustrate the purpose, technical scheme and advantages of the present application, the present application will be further described below in conjunction with the drawings and specific examples.

[0030] The materials used in the examples and comparative examples are commercially available unless otherwise specified.

[0031] The lithium iron phosphate scrap material used in each example and comparative example described herein is a commercially recycled ternary battery, which is a normal retired product without damage, bulging or expansion. The positive electrode sheet contains no additional impurities except the current collector aluminum foil, active material, conductive agent and binder.

[0032] Example 1

[0033] An embodiment of the recycling method of waste ternary batteries described herein comprises the following steps:

[0034] (1) disassembling waste NCM523 (i.e., the active material of the positive electrode material is a nickel-cobalt-manganese ternary material, and the molar ratio of the three elements is 5:2:3) ternary battery under argon atmosphere to obtain a positive electrode sheet;

[0035] (2) calcining the positive electrode sheet at 150°C under a vacuum degree of -0.1 MPa for 2h to obtain a pretreated positive electrode sheet;

[0036] (3) the pretreated positive electrode sheet is placed into a reaction kettle containing an organic extracting solution of pyrrolidone, the solid-liquid ratio is 1:2, then ultrasonic stirring treatment is carried out at 80°C for 1h, the ultrasonic frequency is 24kHz, the power is 32kW, the stirring rate is 120r / min, the obtained suspension is subjected to solid-liquid separation after standing for 4h, the obtained solid is subjected to ultrasonic stirring treatment under the same conditions, and the operation is repeated for three times, the obtained precipitate is subjected to washing, solid-liquid separation, drying and crushing, and the separated active material is obtained;

[0037] (4) the lithium content of the separated active material is detected by an inductively coupled plasma optical emission spectrometer, and the lithium deficiency is determined to be 0.2mol, then the separated active material is crushed in water, 2mol / L lithium acetate aqueous solution is added according to the lithium deficiency in a solid-liquid ratio of 1:2, 0.1vol% additive (a mixture of ascorbic acid and hydrogen peroxide in a mass ratio of 3:1) is added, the obtained mixture is stirred at 100°C at a rate of 200r / min for 4h, and water is supplemented in real time during the reaction to maintain the water level unchanged; after the reaction is completed, the separated solid is dried to a water content of ≤1wt% and crushed to an average particle size of 8μm, and the repaired active material is obtained;

[0038] (5) the repaired active material is mixed with 1mol% inorganic lithium source lithium carbonate, and calcination is carried out at a rate of 2°C / min to 810°C under an air atmosphere for 3h, and the repaired and regenerated positive electrode material is obtained.

[0039] Example 2

[0040] An embodiment of the recycling method of waste ternary batteries described herein includes the following steps:

[0041] (1) the waste NCM111 (i.e. the active material of the positive electrode material is a nickel-cobalt-manganese ternary material, and the molar ratio of the three elements is 1:1:1) ternary battery is disassembled to obtain a positive electrode sheet under an argon atmosphere;

[0042] (2) the positive electrode sheet is calcined at 200°C for 0.5h under a vacuum degree of-0.1MPa, and the pretreated positive electrode sheet is obtained;

[0043] (3) the pretreated positive electrode sheet is placed into a reaction kettle containing an organic extracting solution of pyrrolidone, the solid-liquid ratio is 1:4, then ultrasonic stirring treatment is carried out at 150°C for 0.5h, the ultrasonic frequency is 24kHz, the power is 32kW, the stirring rate is 60r / min, the obtained suspension is subjected to solid-liquid separation after standing for 2h, the obtained solid is subjected to ultrasonic stirring treatment under the same conditions, and the operation is repeated for three times, the obtained precipitate is subjected to washing, solid-liquid separation, drying and crushing, and the separated active material is obtained;

[0044] (4) The lithium content of the separated active material is detected by inductively coupled plasma atomic emission spectrometer, and the lithium deficiency is determined to be 0.4 mol. Then, the separated active material is crushed in water, and 4 mol / L lithium lactate aqueous solution is added according to the solid-liquid ratio of 1:2 according to the lithium deficiency, and 0.2 vol% of an additive (a mixture of ascorbic acid and hydrogen peroxide in a mass ratio of 3:1) is added and mixed. The obtained mixture is stirred at 80°C at a speed of 200 r / min for 4 h. Water is added in real time during the reaction to maintain the water level unchanged. After the reaction is completed, the separated solid is dried to a moisture content of ≤1 wt% and crushed to an average particle size of 8 μm to obtain the repaired active material;

[0045] (5) The repaired active material is mixed with 5 mol% of inorganic lithium source lithium carbonate, and calcined at 850°C at a rate of 5°C / min under air atmosphere for 4 h to obtain the repaired and regenerated positive electrode material.

[0046] Example 3

[0047] An embodiment of the recycling method of the waste ternary battery described herein includes the following steps:

[0048] (1) The waste NCM622 (i.e., the active material of the positive electrode material is a nickel-cobalt-manganese ternary material, and the molar ratio of the three elements is 6:2:2) ternary battery is disassembled to obtain a positive electrode sheet under an argon atmosphere;

[0049] (2) The positive electrode sheet is calcined at 150°C under a vacuum degree of -0.1 MPa for 1 h to obtain a pretreated positive electrode sheet;

[0050] (3) The pretreated positive electrode sheet is placed in a reaction kettle containing an organic extracting solution of pyrrolidone, and the solid-liquid ratio is 1:4. Then, ultrasonic stirring treatment is performed at 150°C for 0.5 h, the ultrasonic frequency is 24 kHz, the power is 32 kW, and the stirring rate is 60 r / min. The obtained suspension is separated after standing for 2 h, and the obtained solid is subjected to ultrasonic stirring treatment under the same conditions for three times. The obtained precipitate is washed, solid-liquid separated, dried, and crushed to obtain a separated active material;

[0051] (4) The lithium content of the separated active material is detected by inductively coupled plasma atomic emission spectrometer, and the lithium deficiency is determined to be 0.4 mol. Then, the separated active material is crushed in water, and 4 mol / L lithium lactate aqueous solution is added according to the solid-liquid ratio of 1:2 according to the lithium deficiency, and 0.2 vol% of an additive (a mixture of ascorbic acid and hydrogen peroxide in a mass ratio of 3:1) is added and mixed. The obtained mixture is stirred at 80°C at a speed of 200 r / min for 4 h. Water is added in real time during the reaction to maintain the water level unchanged. After the reaction is completed, the separated solid is dried to a moisture content of ≤1 wt% and crushed to an average particle size of 8 μm to obtain the repaired active material;

[0052] (5) The repaired active material is mixed with 5 mol% of inorganic lithium source lithium carbonate and calcined at a rate of 5°C / min to 830°C under air atmosphere for 3h to obtain the repaired regenerated positive electrode material.

[0053] Example 4

[0054] One embodiment of the method for recycling waste and old ternary batteries described herein differs from Example 1 only in that the additive is a mixture of ascorbic acid and hydrogen peroxide in a mass ratio of 1:3.

[0055] Example 5

[0056] One embodiment of the method for recycling waste and old ternary batteries described herein differs from Example 2 only in that the additive is a mixture of ascorbic acid and hydrogen peroxide in a mass ratio of 1:3.

[0057] Example 6

[0058] One embodiment of the method for recycling waste and old ternary batteries described herein differs from Example 3 only in that the additive is a mixture of ascorbic acid and hydrogen peroxide in a mass ratio of 1:3.

[0059] Comparative Example 1

[0060] A method for recycling waste and old ternary batteries differs from Example 1 only in that the additive is ascorbic acid.

[0061] Comparative Example 2

[0062] A method for recycling waste and old ternary batteries differs from Example 2 only in that the additive is ascorbic acid.

[0063] Comparative Example 3

[0064] A method for recycling waste and old ternary batteries differs from Example 3 only in that the additive is ascorbic acid.

[0065] Comparative Example 4

[0066] A method for recycling waste and old ternary batteries differs from Example 1 only in that the additive is hydrogen peroxide.

[0067] Comparative Example 5

[0068] A method for recycling waste and old ternary batteries differs from Example 2 only in that the additive is hydrogen peroxide.

[0069] Comparative Example 6

[0070] A method for recycling waste and old ternary batteries differs from Example 3 only in that the additive is hydrogen peroxide.

[0071] Comparative Example 7

[0072] A recycling method of waste ternary batteries, the difference from Example 1 is only that it comprises the following steps:

[0073] (1) disassembling the waste NCM523 ternary battery under argon atmosphere to obtain a positive electrode sheet;

[0074] (2) soaking the positive electrode sheet in a 0.5 mol / L concentration phosphoric acid solution according to a solid-liquid ratio of 1:3 for 1 h, stirring during the soaking process, and after washing, solid-liquid separation, drying, and crushing, obtaining a separated active material;

[0075] (3) detecting the lithium content of the separated active material using an inductively coupled plasma optical emission spectrometer and determining the lithium deficiency amount to be 0.2 mol, then crushing the separated active material in water and adding 2 mol / L lithium acetate aqueous solution according to the solid-liquid ratio of 1:2 according to the lithium deficiency amount, and then adding 0.1 vol% of an additive (a mixture of ascorbic acid and hydrogen peroxide in a mass ratio of 3:1) and mixing, the obtained mixture is stirred at 100°C at a speed of 200 r / min for 4 h, and water is added in real time during the reaction to maintain the water level unchanged; after the reaction is completed, the separated solid is dried to a moisture content of ≤1 wt% and crushed to an average particle size of 8 μm, obtaining a repaired active material;

[0076] (4) mixing the repaired active material with 1 mol% of inorganic lithium source lithium carbonate and calcining at a temperature of 80°C under air atmosphere at a rate of 2°C / min for 3 h, obtaining a repaired and regenerated positive electrode material.

[0077] Comparative Example 8

[0078] A recycling method of waste ternary batteries, the difference from Example 1 is only that the temperature of calcination in step (2) is 80°C.

[0079] Comparative Example 9

[0080] A recycling method of waste ternary batteries, the difference from Example 1 is only that the temperature of calcination in step (2) is 300°C.

[0081] Comparative Example 10

[0082] A recycling method of waste ternary batteries, the difference from Example 1 is only that the temperature of calcination in step (2) is 80°C, and is set to atmospheric pressure.

[0083] Comparative Example 11

[0084] A recycling method of waste ternary batteries, the difference from example 1 is only that the temperature of calcination in step (2) is 300℃, and is set to normal pressure.

[0085] Comparative example 12

[0086] A recycling method of waste ternary batteries, comprising the following steps:

[0087] (1) disassembling waste NCM523 ternary batteries under argon atmosphere to obtain positive electrode sheets;

[0088] (2) calcining the positive electrode sheets at 150℃ under a vacuum degree of-0.1 MPa for 2h to obtain pretreated positive electrode sheets;

[0089] (3) placing the pretreated positive electrode sheets into a reaction kettle containing an organic extracting solution of pyrrolidone, with a solid-liquid ratio of 1:2, and then ultrasonically stirring at 80℃ for 1h, with an ultrasonic frequency of 24 kHz, a power of 32 kW, and a stirring rate of 120 r / min; after the obtained suspension is allowed to stand for 4h, solid-liquid separation is performed, and the obtained solid is subjected to ultrasonic stirring treatment under the same conditions for three times; the obtained precipitate is washed, subjected to solid-liquid separation, dried, and crushed to obtain separated active material;

[0090] (4) detecting the lithium content of the separated active material by inductively coupled plasma atomic emission spectrometry and determining the lithium deficiency amount to be 0.2 mol, then crushing the separated active material in water and adding 2 mol / L lithium acetate aqueous solution according to the lithium deficiency amount with a solid-liquid ratio of 1:2; the obtained mixture is subjected to ultrasonic treatment (frequency 24 kHz, power 32 kW) at 100℃, and is stirred at a rate of 200 r / min for 4h; during the reaction, water is supplemented in real time to maintain the water level unchanged; after the reaction is completed, the separated solid is dried to a moisture content of≤1wt% and crushed to an average particle size of 8μm to obtain repaired active material;

[0091] (5) mixing the repaired active material with 1mol% inorganic lithium source lithium carbonate and calcining at a rate of 2℃ / min to 810℃ under air atmosphere for 3h to obtain repaired regenerated positive electrode material.

[0092] Comparative example 13

[0093] A recycling method of waste ternary batteries, comprising the following steps:

[0094] (1) disassembling waste NCM523 ternary batteries under argon atmosphere to obtain positive electrode sheets;

[0095] (2) calcining the positive electrode sheets at 150℃ under a vacuum degree of-0.1 MPa for 2h to obtain pretreated positive electrode sheets;

[0096] (3) The pretreated positive electrode sheet is placed in a reaction kettle containing an organic extracting solution, pyrrolidone, with a solid-liquid ratio of 1:2, and then ultrasonic stirring treatment is performed at 80°C for 1h, with an ultrasonic frequency of 24kHz, a power of 32kW, and a stirring rate of 120r / min. The obtained suspension is allowed to stand for 4h, and then solid-liquid separation is performed. The obtained solid is subjected to ultrasonic stirring treatment under the same conditions, and the process is repeated three times. The obtained precipitate is washed, subjected to solid-liquid separation, dried, and pulverized to obtain a separated active material;

[0097] (4) The lithium content of the separated active material is detected by inductively coupled plasma atomic emission spectrometry, and the lithium deficiency is determined to be 0.2mol. Then, the separated active material is pulverized in water, and 2mol / L lithium acetate aqueous solution is added according to the lithium deficiency, with a solid-liquid ratio of 1:2. The obtained mixture is stirred at 100°C at a rate of 200r / min for 4h. Water is added in real time during the reaction to maintain the water level unchanged. After the reaction is completed, the separated solid is dried to a water content of ≤1wt% and pulverized to an average particle size of 8μm to obtain a repaired active material;

[0098] (5) The repaired active material is mixed with 1mol% inorganic lithium source, lithium carbonate, and calcined at 810°C at a rate of 2°C / min in an air atmosphere for 3h to obtain a repaired and regenerated positive electrode material.

[0099] Comparative Example 14

[0100] A recycling method of waste ternary batteries, which is different from Example 1 only in that the lithium acetate aqueous solution is replaced by an aqueous solution of lithium carbonate with the same molar amount of lithium ions.

[0101] Example 1

[0102] The liquid content and fluorine content of the separated active material of the recycling method of each example and comparative example are counted, and the aluminum content of the finally prepared repaired and regenerated positive electrode material is detected. Then, these are mixed with commercial PVDF and conductive carbon black at a mass ratio of 8:1:1 to prepare a slurry, which is coated on an aluminum foil to prepare an electrode sheet. Finally, commercial lithium sheets and commercial separators are assembled into lithium ion button cells, and the first discharge specific capacity and the first charge-discharge efficiency are counted under the conditions of 3-4.2V and 0.1C (unit capacity is 160mAh / g) current density, wherein:

[0103] The liquid content (%) is the mass difference of the separated active material after high-temperature drying at 200°C for 24h / the mass of the dried separated active material×100%;

[0104] The fluorine content (%) is the mass proportion of fluorine ions in the separated active material, which is directly obtained by using a fluorine ion selective electrode test method.

[0105] The results are shown in Table 1.

[0106] Table 1

[0107]

[0108] The isolated active material prepared by the method described in Example 2 and the repaired and regenerated material were observed by scanning electron microscopy, as shown in Figure 1 (a) and (b), it can be seen that the repaired and regenerated material prepared by the method described herein has good and complete morphology, and is very close to the active material separated from the positive electrode plate. Further, the two were tested by XRD, and the pure substance new material was compared, as shown in Figure 2 It can be seen that the method described herein has high degree of repair and regeneration of the isolated active material, and the repaired and regenerated material prepared has high purity.

[0109] Finally, it should be noted that the above examples are only used to illustrate the technical solutions herein and not to limit the scope of protection herein. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions herein can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions herein.

Claims

1. A method for recycling waste ternary lithium batteries, characterized in that, Includes the following steps: The positive electrode sheet is obtained by disassembling used ternary lithium batteries; The positive electrode sheet is calcined at 100-200℃ for 0.5-2 hours under a vacuum of -0.1 to -0.2 MPa to obtain a pretreated positive electrode sheet; The pretreated positive electrode sheet was placed in an organic extract and ultrasonically stirred at 80–150°C for 0.5–1 h. The resulting suspension was allowed to stand and then separated into solid and liquid components. The resulting solid was ultrasonically stirred under the same conditions for three times. The resulting precipitate was washed, separated into solid and liquid components, dried, and pulverized to obtain the separated active material. The lithium content of the separated active material was detected to determine the amount of lithium deficiency. The separated active material was then pulverized in water, and an organic lithium salt or its derivative was added according to the amount of lithium deficiency. An additive was then added and mixed. The resulting mixture was stirred at 80–100°C for 1–4 hours, with water added continuously during the reaction to maintain a constant water level. After the reaction was complete, the separated solid was dried and pulverized to obtain the repaired active material. The additive was a mixture of ascorbic acid and hydrogen peroxide, and the volume percentage concentration of the additive in the mixture was 0.1–0.5 vol%. The repaired active material is mixed with an inorganic lithium source and calcined at 750–900°C for 3–6 hours in an air or oxygen atmosphere to obtain the repaired and regenerated cathode material.

2. The method for recycling waste ternary lithium batteries as described in claim 1, characterized in that, The positive electrode material in the waste ternary battery is a nickel-cobalt-manganese positive electrode material, and the molar ratio of nickel, cobalt and manganese in the positive electrode material is (1-8):(1-2):(1-4).

3. The method for recycling waste ternary lithium batteries as described in claim 1, characterized in that, When the pretreated positive electrode is placed in the organic extract and subjected to ultrasonic stirring, the solid-liquid ratio of the pretreated positive electrode to the organic extract is 1:(2-4).

4. The method for recycling waste ternary lithium batteries as described in claim 3, characterized in that, The organic extract is at least one of pyrrolidone, N,N-dimethylformamide, and dimethyl sulfoxide.

5. The method for recycling waste ternary lithium batteries as described in claim 1, characterized in that, The lithium content of the separated active material is detected using an inductively coupled plasma atomic emission spectrometer. The detected lithium deficiency is x, and the molar ratio of lithium in the organic lithium salt to lithium in the separated active material is ≥ x.

6. The method for recycling waste ternary lithium batteries as described in claim 1, characterized in that, The organic lithium salt is at least one of lithium acetate, lithium lactate, LiCF3SO3, and LiN(SO2CF3)2.

7. The method for recycling waste ternary lithium batteries as described in claim 1, characterized in that, The mass ratio of ascorbic acid to hydrogen peroxide in the additive is 1 to 9.

8. The method for recycling waste ternary lithium batteries as described in claim 1, characterized in that, The water content of the reconstituted active substance is ≤1wt%, and the average particle size is 8-12μm.

9. The method for recycling waste ternary lithium batteries as described in claim 1, characterized in that, The inorganic lithium source is lithium carbonate, and the molar ratio of the reconstituted active material to lithium carbonate is 1:0.01 to 0.

05.

10. The method for recycling waste ternary lithium batteries as described in claim 1, characterized in that, The heating rate during the calcination of the repaired active material with the inorganic lithium source is 2–5 °C / min.

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